Method and apparatus for fixing deposited medium by vapor application

ABSTRACT

METHOD AND APPARATUS FOR FUZING PRINTING OR COATING MATERIAL UPON CONVEYED ARTICLES BY THE APPLICATION OF HOT SOLVENT VAPORS IS DISCLOSED HEREIN. A VAPORIZING UNIT IS CONNECTED FOR THE SUPPLY OF SOLVENT VAPOR TO A VAPOR KNIFE INCLUDING A HOLLOW TUBULAR RESILIENT MEMBER HAVING AN ELONGATE VAPOR EMISSION SLOT AND CONTRACTIBLE TOWARD ITS LONGITUDINAL AXIS FOR VARYING THE SLOT WIDTH. RECIRCULATION PROVISIONS WITHDRAW VAPOR FROM ADJACENT THE KNIFE FOR SUBSEQUENT REAPPLICATION AND RECLAIMING PROVISIONS WITHDRAW VAPOR BI-PASSING THE RECIRCULATION PROVISIONS TO RETURN A PORTION OF THE VAPOR TO ITS LIQUID STATE FOR SUBSEQUENT VAPORIZATION. THE RECLAIMING PROVISIONS ALSO DRAW IN AIR TO PREVENT PASSAGE OF AIR INTO THE RECIRCULATION PATH AND COVER PROVISIONS OVERLIE THE KNIFE AND INCLUDE A PIVOTAL GATE MOVABLE BY ARTICLES IN TRANSIT PAST THE KNIFE. THE GATE DIVERTS EMITTED VAPORS TO THE RECIRCULATION PROVISIONS ABSENT THE PRESENCE OF AN ARTICLE PROXIMATE THE KNIFE, MASKS THE LEADING EDGE OF ARTICLES CONVEYED INTO PROXIMITY WITH THE KNIFE AND CONTACTS A SURFACE OF THE ARTICLES DURING TRANSIT PAST THE KNIFE TO AID IN THE PROPER POSITIONING OF SUCH ARTICLES.

Feb. 9, R F. GALITZ 3,561,130

METHOD AND APPAliATUS FOR FIXING DEPOSITED MEDIUM BY- VAPOR APPLICATION Filed Aug. 28, 1968 6 Sheets-Sheet 1 25 Q I 3 FEED cmzo 6 26 22 cmzo D\SCHHRGE w; I f r RECOVERY 24 1 /3 1 k 25 43 BLOWER IFIGJ.

INVENTOR RQYMOND F. GRL\TZ ATTORNEYS R. F. GALITZ 3,561,130

MEDIUM BY VAPOR APPLICATION V 6 Sheets-Sheet 2 METHOD AND APPARATUS FOR FIXING DEPOSITED Feb. 9,11971 Filed A 28. 1968 INVENTOR RAYMOND F. GQUTZ BY x Q WWIGDWLQI )vrmmvfixfs R. F. GALITZ METHOD AND APPARATUS FOR FIXING DEPOSITED Feb. 9', 1971 MEDIUM BY VAPOR APPLICATION Filed Aug. 285 1968 6 Sheets-Sheet 5 Q9. m: H D- INVENTOR RAYMOND P. GRLH'Z ATTORNEYS 9 m2 mm IFIGfS-b Feb. 9, 1971 R. F. GALITZ 3,561,130

, METHOD AND APPARATUS FOR FIXING DEPOSITED MEDIUM BY VAPOR APPLICATION Filed Aug. 28, 1968 6 Sheets-Sheet 4.

) To RECOVERY UHI'T'44 ATT mm 5 Feb. 9, 1971 R. F. GALITZ 3,561,130

. METHOD AND APPARATUS FOR FIXING DEPOSITED MEDIUM BY VAPOR APPLICATION Filed Aug. 28, 1968 6 Sheets-Sheet 5 INVENTOR RAYMOND P. er-m'rz ORNIJYS Feb. 9, 1971 R. F. GALlTZ METHOD AND APPARATUS FOR FIXING DEPOSITED MEDIUM BY VAPOR APPLICATION 6 Sheets-Sheet 6 Filed Aug. 28, 1968 udnm INVENTOR RRYMOND F. GHLITZ Mm ORNEYS United States Patent 3,561,130 METHOD AND APPARATUS FOR FIXING DEPOSITED MEDIUM BY VAPOR APPLICATION Raymond F. Galitz, La Grange, IlL, assignor to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Aug. 28, 1968, Ser. No. 755,889 Int. Cl. F261: 13/00 US. CI. 34-23 31 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for fuzing printing or coating material upon conveyed articles by the application of hot solvent vapors is disclosed herein. A vaporizing unit is connected for the supply of solvent vapor to a vapor knife including a hollow tubular resilient member having an elongate vapor emission slot and contractible toward its longitudinal axis for varying the slot width. Recirculation provisions withdraw vapor from adjacent the knife for subsequent reapplication and reclaiming provisions withdraw vapor bi-passing the recirculation provisions to return a portion of the vapor to its liquid state for subsequent vaporization. The reclaiming provisions also draw in air to prevent passage of air into the recirculation path and cover provisions overlie the knife and include a pivotal gate movable by articles in transit past the knife. The gate diverts emitted vapors to the recirculation provisions absent the presence of an article proximate the knife, masks the leading edge of articles conveyed into proximity with the knife and contacts a surface of the articles during transit past the knife to aid in the proper positioning of such articles.

This invention relates generally to methods and apparatus for fixing or fuzing medium deposited upon articles by the application of solvent vapor to the medium and more specifically to methods and apparatus for fuzing electrostatically deposited printing or coating medium by the application of hot solvent vapors.

The application of solvent vapors to a substrate or article having an image electrostatically produced thereon to effect fixing or fuzing of the toner medium forming such image is known in the art. Typical toner medium may include particles of approximately 41% n-butyl methacrylate and approximately 59% polystyrene or a combination of polyethylene and carbon black. The application of a solvent such as trichloroethylene in a vapor state to an image comprising particles of such toner results in a fixing or fuzing of the discrete toner particles such that the discrete toner particles are fuzed and fixed to the substrate.

In the fixing or fuzing of electrostatically printed images at production rates, the time required for each such fixing or fuzing operation must be substantially reduced if commercial production rates are to be economically attained. Further, the continual applications of solvent vapors to numerous articles in production line fashion requires special attention to the conservation of solvent which, without such special attention, would be substantially wasted in the escape of vapors from the fuzingor fixing station. Similarly, where the articles to be treated are of a card-like or panel-like nature, it is necessary to assure an even application of solvent vapors across the entirety of the printed area to effect a fuzing operation which is consistent throughout the image area of the cards or panels.

In view of the foregoing, it is a primary object of this invention to provide methods and apparatus for fuzing 3,561,130 Patented Feb. 9, 1971 deposited printing or coating medium at production rates and through the efficient employment of solvent vapor.

A further object of this invention is to provide methods and apparatus for applying hot solvent vapor to printed or coated articles to effect fuzing of deposited medium at production rates.

Another object of this invention is to provide methods and apparatus in accordance with the immediately foregoing object wherein recirculation of heated vapor is employed and reclaiming of excess vapor is effected by reduction of such excess vapor to a liquid state.

Additionally, it is an object of this invention to provide apparatus for directing solvent vapor against articles for the fuzing of deposited medium thereon and including provisions for recirculating the applied vapor in addition to provisions for reclaiming excess vapor by the reduction of such excess vapor to a liquid state for subsequent vaporization.

In accordance with the immediately foregoing object of this invention, it is a further object of this invention to provide in the provisions for reclaiming vapor, vapor withdrawal means which withdraws the excess vapor from adjacent the area of application and which further withdraws air or other atmospheric gases from such area, preventing the inclusion of such atmospheric gases in the provisions for recirculating vapor.

Yet another object of this invention is to provide an improved vapor knife apparatus for directing a wide, jet of vapor against a printed or coated article.

An additional object of this invention is to provide in the aforementioned vapor knife an elongate vapor emission opening formed in a hollow tubular member of resilient material, which hollow tubular member is contractible toward its longitudinal axis and expandable away from such axis to effect variation in the width of the emission opening.

Still another object of this invention is to provide in a vapor application system covering provisions including a pivotable gate contactible by articles in motion along a path of conveyance, wherein the gate normally intersects vapors to divert such vapors to recirculation provisions and wherein the gate masks the leading edge of articles so conveyed.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a simplified diagrammatic view of apparatus in accoradnce with this invention and illustrates a vaporizing unit, vapor applying knife provisions fed from the vaporizing unit, vapor recirculation provisions opening adjacent the knife and connected with the vaporizing unit for returning vapor thereto, and vapor reclaiming apparatus for withdrawing additional vapor from the area of application for reduction to a liquid state and reinsertion into a solvent supply.

FIG. 2 is a front elevational view of the apparatus diagrammatically illustrated in FIG. 1 with parts broken away for clarity and shows card or panel conveying provisions, covering means overlying the area of vapor application, vaporizing and pumping provisions for directing vapor into the application area and recirculating vapor to the vaporizer.

FIGS. 3a and 3b, in combination, provide a vertical cross-sectional view taken along the line 3a, fab-3a, 3b of FIG. 2 illustrating the vapor knife including a transversely arranged elongate hollow tubular member, the vaporizer and vapor passage provisions communicating between the vapor knife and vaporizer and including a vapor pumping blower for moving vapor from the vapor izer for application by the vapor knife to card or panellike articles.

FIG. 4 is an enlarged fragmentary vertical cross sectional view taken along the line 44 of FIG. 3a and illus trates a vapor emission opening adjusting stud extending transversely across the hollow tubular member of the vapor knife, a pivotally mounted gate supported by the cover provisions for contacting the leading edges of articles fed therepast and recirculation and reclaiming openings proximate the paper knife for withdrawing vapor from the area of application.

FIG. 5 is a fragmentary vertical cross sectional view taken along the line 55 of FIG. 4 and shows the hollow tubular member of the vapor knife mounted in end plate provisions and further illustrates the mounting of the pivotable gate within the cover provisions.

FIG. 6 is an enlarged fragmentary cross sectional view taken along the line 66 of FIG. 4 and shows the mounting of a pivotable damper within a chamber forming a portion of the vapor recirculation provisions.

Referring to the drawings in detail, indicated generally at 10 in FIG. 1 is a vaporizing unit or vaporizer including a liquid solvent depository or solvent retaining portion 11 having mounted therein a heating element 12 of a suitably selected heater and control combination 13. The vaporizer 10 further includes a vapor outlet 14 connected, via outlet duct provision 15, with a blower 16 which draws vapor from the vaporizer 10 upon driving actuation from a variable speed drive unit and motor combination 17 and a drive train 18.

Hot solvent vapor produced by the heating of a quantity of liquid solvent maintained within the depository 11 is passed through the blower 16 to an output 29 thereof and, via further duct provisions 21, is passed to a vapor knife 22, to be more fully described hereinafter.

Card-like or panel-like articles, one of which is indicated at 23 in FIG. 1, are passed along a predetermined path of conveyance directly above the vapor knife 22 as by the provision of suitably selected conveying means 24 which may include a plurality of conveying or position determining rollers 25 disposed immediately upstream and downstream from the area of vapor application adjacent the knife 22.

Hot solvent vapors emitted in a jet from a vapor emission opening 26 in the vapor knife 22 are directed against an undersurface 27 of the card 23 during passage of the card along its predetermined path of conveyance. A chamber, generally indicated by the numeral 28 and housing the vapor knife 22, is connected via the duct 30 with the upper portion of the vaporizer 10. The blower 16, in withdrawing vapor from the upper portion of the vaporizer 10, applies a reduced pressure to the chamber 28 via the duct 30 and consequently hot vapor is withdrawn into the chamber 28 and recirculated across the level of liquid solvent within the vaporizer 10.

The undersurface 27 of the cards 23 has deposited thereon, as by electrostatic printing, a predetermined image or coating of toner or printing medium soluble with respect to the solvent vaporized within the vaporizer 10. The application of hot vapor from the vapor knife 22 to the undersurface 27 of the card 23, then, fuzes or fixes the printed image or coating thereon. Such fuzing of the deposited printing or coating medium employs a limited quantity of the vapor emitted from the vapor knife 22. However, a relatively large portion of the hot vapor so emitted will be withdrawn into the chamber 28 through the openings 31 and 32 defined therein on each side of the knife 22. Thus, a relatively large portion of the vapor emitted from the knife 22 is recirculated to the vaporizer 10 for subsequent reapplication to cards in transit past the knife 22.

On both the upstream and downstream sides of the chamber 28 are provided two further vapor withdrawal passages 33 and 34 respectively. The passage 33 termimates in an opening 35 closely proximate and upstream from the opening 32 of the chamber 28. Similarly, the passage 34 terminates in an opening 36 closely proximate and downstream from the opening 31 of the chamber 28. Solvent vapor spilled over from the openings 31 and 32 of the chamber 28 are withdrawn through the openings 35 and 36 which serve as intakes to a solvent vapor reclaiming system generally indicated by the numeral 37. The solvent vapor reclaiming system 37 includes, in addition to the passages 33 and 34, manifold duct provisions 38 combining vapor from the passages 33 and 34 and passing the combined vapor to a further duct 41. Application of a reduced pressure to the duct 41 and correspondingly to the passages 33 and 34 may be provided by a blower 42 having an output 43 feeding the vapor passing therethrongh to a recovery unit 44.

The recovery unit 44 may be any of a number of commercially available, known or suitably selected assemblies capable of condensing hot vapor to its liquid state. Condensed solvent liquid is passed via a line 45 to a source of solvent or supply tank 46 for subsequent revaporization by the vaporizer 10.

The supply tank 46 feeds the vaporizer 10 via a supply line 47 and a suitably selected float valve 48 responsive to the liquid solvent level within the vaporizer 10 to maintain a relatively constant predetermined liquid solvent level within the vaporizer.

It will be seen that hot solvent vapor escaping the recirculation provisions constituted by the chamber 28 and its associated duct 30 will pass into the passages 33 and 34. It should further be noted that movement of a card 23 past the vapor knife 22 tends to carry therewith a quantity of the hot solvent vapor applied to the undersurface 27 and such quantity of vapor carried by the card 23 past the opening 31 of the chamber 28 is withdrawn from the undersurface 27 of the card upon approaching the opening 36 terminating the passage 34.

It should be noted that air or other atmospheric gases proximate the area of application of hot solvent vapor to the card 23 is substantially prevented from entering the chamber 28, with a resultant reduction in temperature in the recirculation path, inasmuch as such atmos pheric gases are drawn into the passages 33 and 34 prior to their possible entrance into the chamber 28 via the openings 32 and 31. Accordingly, reduction in vapor temperature by the inclusion of atmospheric gases occurs in the reclaiming provisions of the system wherein a sub sequent reduction in temperature for the purposes of condensation is intended and wherein such reduction in temperature by the inclusion of atmospheric gases does not effect the temperature of the hot vapor applied via the vapor knife 22.

Located atop the hot vapor application area is a cover 50 which aids in locating the cards 23 during their passage along the path of conveyance thereof and which substantially limits the escape of solvent vapor prior to and following the passage of a card past the vapor emission opening 26 of the knife 22. Mounted within the cover 50 is a pivotable gate 51 having a lowermost portion which normally intersects the path of the conveyance of the card 23, causing the gate 51 to be pivoted upon contact with a leading edge of a card in transit through the area of vapor application.

Turning now to FIG. 2, there is shown therein a mounting frame 52 including a base 53 supporting thereon the generally indicated conveying provisions 24. Driving of the conveying provisions 24 may be effected through the employment of a suitably selected motor 54 and suitably selected driving positions 55 which are only diagrammatically illustrated in FIG. 2, the conveying provisions 24 and drive 55 forming, per se, no part of this invention.

A series of mounting feet 56 and upright support members 57 support the vaporizer 10. The feet 56 are provided with threaded levelling means 58 adjustable to provide levelling of the vaporizer with respect to the liquid solvent contained therein.

A frame 52 additionally includes a generally horizontally disposed mounting platform 60 connected via a generally vertically extending upright 61 with the base 53 and further supported by a diagonally extending support bar 62. The platform 60 mounts the variable speed drive unit and motor combination 17 which drives the blower 16 to withdraw vapors from the vaporizer 10 and recirculate vapors through the varporizer. The combination 17 may be any of a number of suitably selected or commercially available combinations including a motor 63 and a variable speed output box 64 which, by actuation of a manually operable control 65, varies the speed imparted to the blower 16. The output from the variable speed drive unit and motor combination 17 is applied to the blower 16 via the drive 18 including an output pulley 66 over which is entrained a belt 67 in driving engagement with a further pulley 68 mounted upon a shaft 70, which shaft 70 serves as the input to the blower 16.

The blower 16 includes an input port 71 joined as at 72 with the duct provisions which communicate with the vaporizer 10 as indicated at 73. The output portion of the blower 16 is, as best seen in FIG. 3a, connected at the flanges 74 with a first passage providing duct 75 constituting a portion of the duct provisions 21 leading to the vapor knife 22. A second portion of the duct provisions 21 is provided by a short upwardly extending duct 76 which increases in cross sectional area in an upward direction and which is connected with the duct 75 at the flanges 77. The chamber 28 forming a portion of the recirculation provisions described hereinabove with respect to FIG. 1 includes a pair of front and rear sloped side walls 78 and 79, respectively, joined by a further connecting wall 81, all of which is best illustrated in FIGS. 3a and 3b.

Within the chamber 28 a further generally upwardly opening duct 82 communicates with the vapor knife 22 to supply hot solvent vapor thereto for application to a conveyed article. The generally upwardly opening duct 82 within the chamber 28 communicates with the upwardly extending duct 76 located externally of the chamber 28 via a connector 83 which extends through the connecting wall 81 of the chamber 28. The ducts 76 and 8-2 are flanged at 84 and 85, respectively, and secured to the connector 83.

The duct 82 within the chamber 28 supplies hot vapor through the chamber 28 to the vapor knife 22 and terminates at its uppermost portion in a partially cylindrical flange 86 which is secured to the knife 22 by a plurality of fasteners 87. The vapor supplying duct 82 communicates with the interior of the vapor knife 22 through an opening 88, best illustrated in FIG. 4, formed in a generally cylindrical, hollow tubular member 90 which constitutes the body of the vapor knife 22. The hollow tubular member 90 is of steel or similarly resilient material and, as best seen in FIGS. 3a and 3b extends transverse to the path of conveyance in the articles to be treated. The vapor emission opening 26 through which hot solvent vapors are applied to the undersurface 27 or cards or panels 23 in transit past the knife 22 is provided by an elongate narrow slot extending axially the length of the tubular member 90.

Adjustment of the width of the slot 26 in the circumferential direction with respect to the tubular member 90 is effected by the provision of a pair of studs 91 extending diametrically through the hollow tubular member 90 and having an enlarged head portion 92 and a Washer 93 contacting the exterior of the hollow tubular member 90. T hreadedly received upon the studs 91 is a nut 94 which contacts the exterior of the tubular member 90 diametrically opposite the head 92 and which may be affixed to the exterior of the tubular member as indicated in FIG. 4. It will be seen that turning of the stud 91 in a tightening direction will effect reduction in the width of the vapor emission slot 26 through a contraction of the tubular member inwardly toward its longitudinal axis whereas a loosening of the stud 91 effects a relaxation in the pressure applied to the tubular member 90 allowing the enlargement of the vapor emission slot 26 under the inherent bias provided by the resilient material of which the tubular member 90 is formed.

Mounting of the vapor knife 22 within the chamber 28 is provided by a pair of mounting plates 95, 96 having generally annular grooves 97, 98, respectively, formed in the interior surfaces thereof and receiving respective ends of the hollow tubular member 90 therein. An annular bearing member is received in each of the slots 97 and 98 and contacts the respective end of the tubular member 90 located therein. A suitably dimensioned wave washer 101 is located in each of the slots 97 and 98 between the bottoms thereof and the bearing members 100 biasing the bearing members 100 into firm engagement with the respective ends of the tubular member 90. Each of the end or mounting plates 95 and 96 is supported upon an upright apertured plate 102 as by a bolt 103. Each of these plates 102 includes a central aperture 104 through which extends the tubular member 90 for reception in the slots 97, 98. The apertured plates 102 terminate the cavity 28 in which the knife 22 is located on either side of the path of conveyance and are joined with the walls 78 and 79 adjacent opposite ends of the vapor knife 22. The apertured plates 102 and mounting plates 95 and 96 are supported by mounting provisions generally indicated by the numeral 105 in FIGS. 3a and 3b which support the knife 22 upon the members of the supporting base 53.

The chamber 28 into which hot vapor is drawn for recirculation terminates in a port 106 best seen in FIG. 3b, which port is connected, via a curved conduit 107, with a recirculated vapor intake port 108 provided at one end of the vaporizer 10. The conduit 107 constitutes the duct 30 of FIG. 1 and is flanged and connected at its ends 110 and 111 to the chamber 28 and vaporizer 10, respectively.

Vapor recirculated through the chamber 28, conduit 107, across the level of the liquid within the vaporizer 10 and returned to the vapor knife 22 is maintained at an elevated temperature provided by both the heater 13 of the vaporizer 10 and an ancillary heater 112 mounted upon the mounting plate 95 and having an elongate heating element 113 extending into the interior of the hollow tubular member 90. The ancillary heater 112 may be a suitable commercially available heater and serves to further elevate the temperature of solvent vapor prior to jet-like emission from the elongate vapor emission opening 26 of the knife 22.

A suitable commercially available thermocouple temperature sensing device 114 may be mounted upon the mounting plate 96 with an elongate bi-metallic temperature responsive element 115 extending into the interior of the tubular member 90 to detect the temperature of the vapor just prior to emission from the Opening 26. The thermocouple 114 may be employed to control the ancillary heater 112 for automatic control of the temperature of the hot solvent vapor applied to articles in transit past the knife 22.

The passages 33 and 34 which terminate in openings 35 and 36, respectively, through which vapor spilled over from the chamber 28 is withdrawn, are provided by two large downwardly depending conduits 116 and 117, best illustrated in FIG. 4. The conduits 116 and 117 are joined at a flanged end 118 thereof, best illustrated in FIG. 3b, with the manifold 38 for passage of vapor to the recovery unit 44 via the duct provisions 41. The conduits 116 and 117 are spaced slightly from the chamber 28 and the space 120 so provided on each side of the chamber 28 may be employed for jacketing the chamber in insulating material to further help maintain the temperature of solvent vapor in the recirculation path.

It will be noted from FIG 4 that the vapor emission opening 26 of the vapor knife 22 is directed angularly toward the path of the conveyance of the treated articles in an upstream direction with respect to that path of conveyance. The angle at whjch hot solvent vapor leaves the tubular member may be adjusted and pre-set by a rotation of the tubular member '90 about its axis and within the slots 97 and 98 of the mounting plates and 96 prior to fastening of the tubular member 90 with the duct 82. The gate 51 pivotally mounted within the cover 50 overlying the vapor application area is mounted slightly upstream with respect to the vapor emission opening 26 and defines a surface thereon which, in the absence of a card or panel 23 within the vapor application area, intersects the path of vapor emission from the vapor emission opening 26 to maintain vapor so emitted in the area of the openings 31 and 32 of the chamber 28 to assure withdrawal of a substantial portion of the vapor through the chamber 28 for recirculation and to reduce substantially vapor losses along the conveyance path, absent the presence of a card or panel 23. A lowermost portion 121 of the gate 51 intersects the path of conveyance of the cards or panels 23 as defined by a set of guiding provision 122, 123 and 124. It will be seen from FIG. 4 that the lowermost portion 12-1 of the pivotally mounted gate 51 masks the leading edges of articles in transit along the path of conveyance fromvapor emitted through the opening 26 of the vapor knife 22. Such masking action is of particular benefit where the cards or panels 23 are of corrugated medium extending parallel to the path of conveyance defined openings in the leading edge of the paperboard panels susceptible to the entrance of vapor therein. The masking action provided by the portion 121 of the gate 51, then, prevents entrance of vapor into the openings which ordinarily would be exposed to the jet or stream of hot solvent vapor from the vapor knife 22. Additionally, it will be noted that the cover 50 has mounted therein a stop 122 for contacting the surface 120 of the gate 51 upon movement of the gate by the leading edge of a panel 23 in transit therepast. Once pivoted to the position shown in broken lines in FIG. 4, the lowermost portion 121 of the gate 51 contacts the upper surface of the panel to aid in maintenance of the panel in close proximity to the vapor emission opening 26 as vapor is applied to the undersurface of the panel.

As best seen in FIGS. 3a, 3b and 5, the cover 50 extends the full width of the path of conveyance and is provided with a pair of handles 123, facilitating the manual placement and removal of the cover 50. The cover 50 terminates in a pair of front and rear side walls 124 and 125, respectively, each of which has an aperture 126 formed therein closed by cover plate 127, fastened to the walls 124 and 125 as by the bolts 128. Through the apertures 126 extend a pair of bearing projections 130 integrally formed upon the interior surface of the cover plates 127 and defining a centrally located bore 131 therein. Within the bores 131 are received closely fitting cylindrical ends 132 of a rotatable gate support bar 133. The gate 51 is afiixed, as at 134, upon the gate support bar 133, the cylindrical end 132 of the bar 133 being rotatably slid-able Within the bores .131. The walls 124 and 125 of the cover 50 are spanned by a hood 135 to complete the enclosure of the vapor application area.

Adjustments of the flow of hot solvent vapor into the chamber 28 is provided by the inclusion of a pair of dampers and 141 immediately below the openings 32 and 31, respectively, and adjacent the exterior of the hollow tubular member 90 of the knife 22. The dampers 140 and 141 are each supported upon a pair of damper support members 142, one of which is best illustrated in FIG. 6. The damper support members 142 are of generally cylindrical configuration relieved along a portion of the surface thereof as at -143 for connection with the dampers as by the screws 144. Each of the damper support members 142 extends into an aperture 145, four of which are provided in the upright plate 102. A shaft portion 146 extend through a further plate 147 affixed to the upright plate 102 and terminates in an end 148 of generally rectangular cross-section, exterior of the cavity 28 and allowing manual variation of the angle of inclination of the dampers 140 and 141. The shaft 146 is threaded as at 150 to allow the provision of a lock nut 151 suitable for maintaining the associated damper at a desired angle of inclination.

Air intake into the passages 33 and 34 from adjacent the area of application of hot solvent vapor is adjustable by the provision of movable panel members 152 mounted upon the conduits 116 and 117 as by the provision of outwardly extending studs \153 slidably maintained within slots 154 formed in the outermost walls of the conduits 116 and 117. Threadedly maintained upon the studs 153 are adjustable retaining members 155 having projections 156 formed thereon for engagement with the walls of the conduits 116 and 117 adjacent the slots 154. Movement of the panel members 152 as indicated by broken line illustration in FIG. 4 allows reduction in the cross sectional area of the openings 35 and 36 into the passages 33 and 34, respectively, and allows restriction of air flow into such passage by movement of the panel members 152 into closer proximity with the path of conveyance of the cards or panels 23.

Varying the angle of inclination of the dampers 140 and 141 adjust the amount of hot solvent vapors spilled over from the chamber 28 to the passages 33 and 34, while adjusting the position of the movable panel members 152 allows an adjustment in the amount of air or atmospheric gases entering the passages 33 and 34, thus preventing the entrance of excess atmospheric gases such as would cause withdrawal of those gases into the chamber 28.

As set forth hereinabove, a portion of the hot solvent vapor applied to articles in transit along the path of conveyance is carried with such articles and ultimately withdrawn into the passage 34. The rate of vapor produc tion, then, by the vaporizer 10 should be adjusted to provide vapor as required by the use thereof in fixing or fuzing the coating or printing medium on the undersurface of the panels 23, by the withdrawal of vapor carried with the panels in their movement through the vapor application area, by the slight vapor losses occurring in the system and to provide an amount of vapor spilled over past the openings 31 and 32 into the chamber 28 to be withdrawn by the passages 33 and 34 for conversion to the liquid state.

It will be seen from the foregoing that adjustment of the vaporization of the vaporizer 10, the driven rate of the blower 16 and the position of the dampers 140 and 141 and the panel members 154 allows employment of the system to maintain elevated vapor temperatures in the recirculation path, decreasing the time required in each fuzing operation, with minimum loss of solvent and with little or no entry of atmospheric gases into the recirculation path.

While the methods and apparatus described hereinabove represent preferred forms of the embodiment, it will be readily apparent that many variations may be made therein without departure from the spirit of the invention embodied therein.

I claim:

1. Fuzing apparatus for fixing deposited printing or coating medium to articles by the application of vapor thereto including means for vaporizing a liquid solvent to form a solvent vapor, vapor applying means for directing solvent vapor produced by said means for vaporizing against one of said articles, means for locating said articles for the application of vapor thereto, vapor recirculation means for removing vapor from adjacent said article for reapplication thereto and vapor reclaiming means in addition to said vapor recirculation means for collecting a portion of the solvent vapor directed against said article and converting the collected solvent vapor to a liquid form for subsequent vaporization.

2. Apparatus according to claim 1 wherein said vapor recirculation means defines first vapor inlet means adjacent said vapor applying means for withdrawing vapor immediately adjacent the area of application of said vapor to said article, said vapor reclaiming means including second vapor inlet means adjacent said first vapor inlet means and on the opposite side of said first vapor inlet means from said vapor applying means for withdrawing vapor passing said first vapor inlet means and substantially preventing intake of atmospheric gases by said first vapor inlet means into said vapor recirculation means.

3. Apparatus according to claim 2 wherein said first and second inlet means are closely proximate the location of said article, said second inlet means including at least one adjustable panel mounted for movement toward and away from said article to adjust intake of atmospheric gases to said vapor reclaiming means and movable to vary the cross-sectional area of said first inlet means.

4. Apparatus according to claim 3 wherein said recirculation means includes adjustable damper means located therein for partially restricting vapor passage from said first vapor inlet means.

5. Apparatus according to claim 1 wherein said means for locating said article comprises means for directing movement of articles along a path of conveyance, said means for directing solvent vapor against one of said articles including outlet means proximate said path of conveyance for passing vapor therethrough to an trticle and first passage means connecting said outlet means with said means for vaporizing, said recirculation means including first inlet means opening proximate said path of conveyance and second passage means connecting said first inlet means and said means for vaporizing, said outlet means being located centrally within said first inlet means and said reclaiming means comprising second inlet means proximate said path of conveyance and including inlets on opposite sides of said first inlet means for withdrawing vapors passing said first inlet means and for substantially preventing the entrance of atmospheric gases into said first inlet means.

6. Apparatus according to claim 1 wherein said means for vaporizing includes liquid retaining means and heater means mounted within said liquid retaining means for heating liquid solvent therein to produce solvent vapor, said means for directing solvent vapor against one of said articles including outlet means for passing solvent vapor therethrough and pump means for moving solvent vapor from said means for vaporizing to said outlet means, said recirculation means comprising inlet means adjacent said outlet means and passage means interconnecting said inlet means and means for vaporizing for passing vapors from said inlet means and through said means for vaporizing for reapplication to an article.

7. Apparatus according to claim 1 wherein said means for directing solvent vapor against one of said articles includes a vapor knife, means communicating between said vapor knife and said means for vaporizing, said vapor knife including a hollow tubular member having an elongate opening formed axially along the surface thereof for passing vapors therethrough and into contact with said articles and an intake opening connected with said passage means for passing vapors from said vaporizing means to the interior of said knife.

8. Apparatus according to claim 7 further comprising heater means mounted within said hollow tubular membgr for heating vapor just prior to passage through said elongate opening.

9. Apparatus according to claim 7 wherein said hollow tubular member is of resilient material and includes means for contracting said tubular member to reduce the circumferential extent of said elongate opening.

10. Apparatus according to claim 8 wherein said means for contracting said tubular member includes at least one elongate stud extending laterally through said tubular member and bearing enlarged tubular member contacting members at opposite ends thereof and in contact with the exterior of said tubular member, one of said enlarged tubular member contacting members being adjustably received upon said stud for contracting said tubular member against the bias of said resilient material upon movement inwardly with respect to said tubular member and for allowing expansion of said tubular member under the bias of said resilient material upon movement outwardly with respect to said tubular member.

11. Apparatus according to claim 7 wherein said knife further includes two end plates closing and mounting said tubular member at opposite ends thereof, said plates including means for allowing angular movement of said tubular member about its longitudinal axis to pre-set the angle of emission of vapor from said elongate opening.

12. Apparatus according to claim 1 wherein said means for locating said article includes means for directing movement of the article along a predetermined path, said means for directing solvent vapor against one of said articles including vapor knife means located proximate said predetermined path for directing a stream of vapor toward said path, cover means adjacent said path and on the opposite side thereof from said vapor knife means and including a swingably mounted gate extending into said path for swinging under contact with leading edges of articles in transit on said path.

13. Apparatus according to claim 12 wherein said gate is located upstream along said path with respect to said vapor knife means and includes a surface lying in the fiow path of the vapor stream from said vapor knife means to divert at least a portion of the vapor stream to said recirculation means prior to swinging movement of said gate by an article in transit on said predetermined path.

14. Apparatus for fixing deposited printing or coating medium to articles by the application of vapor including means for guiding articles along a predetermined path of conveyance, vapor application means for directing a stream of vapor onto said articles during their movement along said predetermined path, means for withdrawing vapor from the area of application, cover means located proximate said vapor application means and on the opposite side of said predetermined path from said vapor application means, said cover means including a pivotally mounted gate normally intersecting a stream of vapor from said vapor application means for substantially preventing escape of vapor from said means for withdrawing vapor and said gate extending into said predetermined path for pivotal movement by contact with articles. in transit on said path for masking the leading edge of articles prior to movement into contact with said gate.

15. Apparatus for fixing deposited printing or coating medium to serially conveyed panels including means for guiding movement of the panels along a predetermined path, vapor application means for directing a stream of vapor against a surface of said panel during movement thereof along said path, cover means located proximate said vapor application means and on the opposite side of said path from said vapor application means, said cover means including a gate having a portion normally intersecting said path and lying in the stream of vapor from said vapor application means, said gate portion intersecting said predetermined path being located for contacting leading edges of panels in transit on said predetermined path and movable by said panels to contact the surface of said panels nearest said cover means during movement of said panels past said gate and to mask the leading edges of said panels from said stream of vapor prior to movement of said panels past said gate.

16. Apparatus according to claim 15 further including means for withdrawing vapor from the area adjacent said vapor application means, said gate substantially prevent- 1 1 ing the escape of vapor past said means for withdrawing during absence of a panel proximate said vapor application means.

17. Fuzing apparatus for fixing deposited printing or coating medium to serially conveyed panels including means for guiding movement of panels along a predetermined path, vapor knife means extending transversely of said path for directing a wide, thin solvent vapor stream against a surface of said panels during movement along said path, vaporizing means, means connecting said vaporizing means with said vapor knife means, vapor recirculation means including an open ended chamber adjacent said path and means connecting said chamber with said vaporizing means, said vapor knife means being located within said chamber adjacent the open end thereof and means for circulating vapor for emission from said vapor knife means and for returning vapor to said vaporizing means through said chamber.

1S. Apparatus according to claim 17 wherein said vapor knife means includes a vapor emission opening, an interior chamber and vapor heating means within said interior chamber for heating vapor during passage through said chamber to said vapor emission opening.

19. Apparatus according to claim 17 further comprising vapor reclaiming means including channel means Opening adjacent said open end of said open ended chamber for withdrawing vapor passing said chamber means and for substantially preventing atmospheric gases from entering said chamber by drawing said atmospheric gases into said channel means before passage thereof to said chamber.

20. Apparatus according to claim 19 wherein said vapor reclaiming means comprises means for converting vapor entering said channel means to a liquid state for revaporization, said channel means being located closely proximate at least one edge of the open end of said open ended chamber to withdraw vapors spilled over the open end of said open ended chamber.

21. Apparatus according to claim 17 further including liquid solvent supply means, said vaporizing means including means for maintaining a quantity of liquid solvent therein, heater means for heating said liquid solvent to produce solvent vapor, said means for maintaining a quantity of liquid solvent including level responsive means for controlling the addition of liquid solvent to said vaporizing means in dependence upon the liquid level within said vaporizing means.

22. Apparatus for fixing deposited printing or coating material on articles in transit along a predetermined path including vaporizing means for producing hot solvent vapor from liquid solvent, means for applying said hot solvent vapor to articles in transit along said predetermined path, recirculation means for withdrawing said hot solvent vapors from adjacent said predetermined path and vapor reclaiming means for converting hot vapor to liquid for revaporization including means for withdrawing vapor and atmospheric gases from adjacent said recirculation means to recapture vapor passing said recirculation means and to prevent cooling of vapor in said recirculation means by the drawing of atmospheric gases into said recirculation means.

23. Apparatus according to claim 22 wherein said means for applying said hot solvent vapor includes vapor knife means for directing a stream of vapor against articles in transit on said path, said vapor knife means including ancillary heating means for heating vapors during passage through said knife means.

24. The method of applying solvent vapor to articles having printing or coating medium deposited thereon including the steps of vaporizing a liquid solvent to produce solvent vapor, directing the solvent vapor into a predetermined area for application against the article, withdrawing a portion of the solvent vapor from the predetermined area, recirculating the portion of solvent vapor for reapplication to an article and reclaiming an additional portion of the solvent vapor including withdrawing the additional portion of solvent vapor from the predetermined area and converting the additional portion to liquid solvent.

25. The method according to claim 24 wherein said step of reclaiming includes withdrawing a quantity of atmospheric gases from adjacent said predetermined area to substantially preclude withdrawal of atmospheric gases in said step of withdrawing the first mentioned portion of solvent vapor.

26. The method according to claim 25 wherein said step of vaporizing includes heating the solvent liquid to produce hot solvent vapors, said method further including additionally heating the solvent vapor just prior to direction into the predetermined area.

27. The method according to claim 24 wherein said step of vaporizing includes heating a quantity of liquid solvent within a vaporizer to produce hot solvent vapor, said step of recirculating including directing the first mentioned portion of solvent vapor withdrawn from the predetermined area into the vaporizer for reapplication.

28. The method of applying solvent vapor to articles having printing or coating medium deposited thereon including the steps of serially conveying articles along a predetermined path of conveyance, generating solvent vapors, directing the solvent vapor against the articles in a wide, thin jet disposed transverse to the path of conveyance, withdrawing a first portion of vapor from adjacent the jet of vapor including sucking vapors from areas along the path of conveyance immediately upstream and downstream from the jet of vapor, recirculating the first portion of vapor for inclusion in the jet, withdrawing a second portion of vapor including sucking vapor from areas along the path of conveyance immediately upstream and downstream from the areas at which the first step of withdrawing occurs to reclaim vapor in addition to the first quantity of vapor and converting the second quantity of vapor to a liquid state for subsequent vaporization.

29. The method according to claim 28 wherein the step of withdrawing a second portion of vapor includes drawing atmospheric gases from adjacent the path of conveyance to substantially prevent inclusion thereof in the first step of withdrawing.

30. The method according to claim 29 wherein the step of vaporizing includes producing hot solvent vapor, said step of drawing atmospheric gases preventing lowering of the temperature of the recirculated vapor by the inclusion of atmospheric gases therein.

31. The method according to claim 28 wherein the step of vaporizing includes producing vapor at a rate at least equal to the sum of the rate at which the second portion of vapor is withdrawn, the rate at which vapor is employed in the fuzing of medium on the articles, and the rate at which vapor escapes the first and second steps of withdrawing.

References Cited UNITED STATES PATENTS 2,726,166 12/1955 Greaves 34-155X 2,974,512 3/1961 Carter 34155X 3,383,775 5/1968 Jacob et a1. 34l55X CHARLES SUKALO, Primary Examiner US. Cl. X.R. 34155, 219 

